Current-regulator.



YNO. 821,936.

PATENTED MAY 29, 1906.

W. K. GIBBONEY.

CURRENT REGULATOR. APPLICATION FILED NOV. 19, 1904.

UNITED STATES P TENT OFFICE.

WILLIAM K. GIBBONEY, OF BUFFALO, NEW YORK, ASSIGNOR TO THE PITTSBURGHREDUCTION COMPANY, OF NEW KENSINGTON,'PENN- SYLVANIA, A CORPORATION OFPENNSYLVANIA.

Specification of Letters Patent.

CURRENT-REGULATOR.

Patented m yee, 1906.

Application filed November 19, 1904. Serial No. 233,391-

my invention.

My invention has been especially designed for the regulation of a groupof electrodes in an electric furnace by which they can be reg- .ulatedindependently and automatically, so as to maintainconstant and uniformconditions, and by which, if desired, the current applied to all theseveral electrodes may be varied and adjusted simultaneously. Where anumber of electrodes are used in a single electric furnace regulation ofthis kind is of the current supplied to the electrode may be varied asdesired.

In the accompanying drawing I show two electrodes 2 2, which areregulated by the apparatus which I am about to describe; but

the invention can be ap lied to the regulation of any number of eectrodes, all that is essential being to provide each of them or eachunitary group of them with individual regulating devices constructed inaccordance with my mvention.

- The electrodes 2 '2 are supplied with current from a circuit 3 and agenerator 4, which may be an alternating-current generator, as shown onthe drawing, or it may be a generator of direct current. Each electrode1s provided with a mechanical feeding device by means of which it iseither raised or lowered in accordance with the current conditionsnecessary to be maintained.

I do 'not show the feeding mechanism in the drawing; but it maybe. of.any suitable type, and it is controlled by my improved regulating.device. This device in theform in which I show it comprises anoscillatory armature 4, mounted between poleieces 5, the field beingconstituted by 00' s 6 6, wound u on the ole-pieces. The strength of thefie d is reglfiated by a rheostat 7, and preferably also by a rheostat8, which is in the circuit with the armature-coil, the field andarmature coils being in the circuit which is independent of the circuittobe controlled :and is preferably constant, or nearly so, so

that a'torque of constant force capable of manual regulation by means ofrheostats 7 and 8 is applied to the armature 4. The inde endentarmature-circuit is not indispensa le, since the device may be operatedwith the armature-coils short-circuited, or these coils may be removedaltogether.. The armature-shaft carries a lever 9, at each end of whichare contacts 10 and 11', respectively adapted to' dip into mercury-cups12 13. These cups are in 'circuits'14 15, sup lied from a suitablesource 16 and-contro ing, respectively, the magnets 17 and 18, one ofwhich controls the actuating mechanism for raising the electrode and theother of which controls the mechanism by which the electrode is lowered,so that if one of the contacts is made at the mercury-cups theelectrode.

will be lowered, and if the contact is made at the other cup theelectrode will be depressed in the furnace, thereby increasing ordiminishing the resistance of the electrode-circuit and correspondinglydiminishing or increasing the current fiowin 19 is a magnet which I showin the drawing as a solenoidmagnet.

as shown in the drawing, in a circuit with a series converter 20, bywhich a current of less voltage, but varying directly with the currentin the main circuit, is supplied to magnet 19. This magnet has anarmature 21 attached to the lever 9, which tends to draw the lever down,and thus move it in opposition to the constant force applied to it byarmature 4. The motion of the lever is restricted b the post 22, havingsuitable stops 22. Ifbwever, if a direct current is used the de- Wherean alternating current is used, it is preferably arranged, 9o

IOO

rived re ulating-current will be obtained by so that the torque of thearmature will be just sufficient to counterbalance the pull of thesolenoid-magnet 19 when the electrode is in proper position in thefurnace and a normal current is passin through it. This will keepthelever 9 in a h will hold both of the contacts 10 and 1 1 out of themurcury-cups, and therefore neither of the electromagnets 17 or 18 willbe actuated and the electrode will remain stationary in the furnace. If,however, the electrode should be too high in the furnace, the resistanceof its circuit being'increased thereby less force will be exertedthrough magnet 19 on the armature 21, so that'the torque of the armature4 will overbalance the action of the magnet 19 and will move the leverso as to make contact in the mercury-cup 12 The current will thereuponflow through the magnet 18, which will cause the feeding device to movethe electrode down in the furnace, thus lowering the resistance of theelectrodecircuit and increasing the current whichpasses through it. Whenthe current has reached a point high enough to exert upon the armature21 a force sufficient to counterbalance the torque of the armature 1, itwill move the lever 9 and will open a circuit at the mercurycup 12, thusdener'gizing the magnet 18 and causing the feed of the electrode tostop. llf the current passing through the electrode should increase, anincreased pull will be exerted by the magnet 19, which will move thelever 9 sufficiently to make contact at the mercury cup 13. This willenergize the ma net 17, which in turn will control the feeding mechanismof the electrode, so as to raise it in the furnace until it has reacheda point where the current is restored to its normal condition. The forceexerted by the magnet 19 will then balance the torque of armature 4,again opening circuit at 13, so that the electrode will come to rest. Inthis way the apparatus will respond quickly to very slight changes inthe position of the elec trode and the current passing therethrough,each electrode being individually regulated by its own mechanism and allthe electrodes of the furnace being kept in such positions as tomaintain constant conditions'of resistance and of current in theirrespective circuits.

I may regulate the current which is sup plied to any electrode not onlyby operation of rheostats 7 and 8, but by a switch 23, by whichone ofthe field-coils 6 may be cut out of the circuit and the current passingthrough the corresponding electrode thus decreased to about one-half thequantity at which the de-V vice was originally adjusted. This is oftenimportanteas, for example, when by reason of defective composition someof the electrodes may become unduly heated. In such case the current inthese electrodes can be 6' lowered without aifecting the current passingthrough the other and normally acting elecorizontal position and trodes.The current may thus be regulated manually in any one or in all of theelectrodes by cutting out of circuit one of the field-coils of one orall of the regulating devices.

t will be understood b those skilled in the art that the mechanismescribed above may be varied in man ways, although I deem the form whichI i lustrate to be preferable. Thus instead of the solenoid-magnet 19and the motor 4 5 other forms of electromagnetic devices may besubstituted, the essential being only that the magnetic regulator bywhich the current is controlled is opposed by an electromagnetic device.This has great advantages over the use of a spring or a weight for theopposing force, because it can be ad justed with reat accuracy and isnot subject to the distur ing influences which impair the value ofadjustable springs or weights. I also find that a weight 2 1, travelingon a screw 25, attached to the lever 9, assists materially in giving abetter regulation, as such adjustable counterpoise can be shifted towardor from the axis of rotation, and the opposing electromagnetic force canbe slightly varied, as desired. 1 show this construction in the drawing.

The apparatus may be modified in many ways, since What I claim is 1.Means for regulating furnace-electrodes, consisting of motive devicesarranged to move the electrode in opposite directions, normally opencircuits for the motive devices, an electromagnetic regulating deviceoperated by current derived from the electrode-circuit and proportionalthereto, said device being arranged to control the circuits of themotive devices, and a magnetic device arranged to. oppose the action ofthe regulating device and energized from a separate source;substantially as described.

2. Means for regulating furnace-electrodes,

,comprising motive devices for feeding the electrode, normally opencircuits for the motive devices, an electromagnetic regulating deviceoperated by current derived from the main current and proportionalthereto, said regulating device controlling the circuit of the motivedevices, a magnetic device arranged to oppose the action of the saidregu lating device energized from a separate source, and means forvarying the force of the opposing magnetic device; substantially asdescribed.

. 3. The combination with a' roup ofelectrodes, eath of which isprovided with motive devices for raising and lowering it, ofelectromagnetic regulatin devices operated by current derived from t emain current and proportional thereto, each of the regulating devicesbeing arranged to control the circuits of the motive devices of one ofthe electrodes,

magnetic devices energized from a separate source, and arranged tooppose the action of the first-named regul'atin devices andmeans foradjusting the orce o the opposing magnetic devices; substantially asdescribed.

' 4. In means for regulatin furnace-electrodes, the combination .witseparate motive devices for raising and lowering the electrode, of aregulator comprising an armature and field, 1n circuit w1th a source ofcurrent v inde endent of the current to be regulated,

consisting of separate motive devices for raising and lowering theelectrode, normally open circuits therefor, an armature and field incircuit with a source of currentinde endent of the current to beregulated, an electromagnetic devieeoperated by a current derived fromthe main current and .proportional thereto, and circuit-controllingmeans for the circuits pf the motive devices operated by the opposingactions of said armature and elec tromagnetic device, together withmeans for regulating the tor ue of the armature; substantially as descried.

6. A current-regulator, com rising an armature and field in circuit wita source of current independent of the current to be regulated, normallyopen circuits including motive devices, a lever carried by thearmatureshaft, and carrying contact devices for controlling saidcircuits, and an electromagnetic device operated by a current derivedfrom the main current and proportional thereto and acting upon saidlever in opposition to the armature, together with means for adjustingthe force ofthe opposing actions of said armature and electromagneticdevice; substantially as described. p

In testimony whereofI have hereunto set my hand.

-NORWOOD P. KEEN, GEORGE B. BARRELL.

